potterton prima f50

[dotto]

hi guys i would really appreciate your expertize on this issue. I have an open vent system with 2*2port valve and a Potterton Prima F50. The ch mv needed changing as the micro switch was sticking. I changed it, refill the system, bled the rads and called for hw. The boiler fired ok, then i called for ch, the new mv moved over to open position, the pump started running, i went downstairs to see whether the boiler fired up but unfortunately nothing happened, not even the fan started whirling. I went back upstairs, bled the air vent situated in the highest point of the system by the hwsc, quite a lot of air was pushed out but still no luck. At that point , i called for hw and this time not even with hw call the boiler fired. I must say that in winter i experienced something peculiar with the fan thus once the hw or ch were satisfied the fan kept whirling for at least 30 min until i switch the boiler switch off and then put the switch back on. That didn't happened all the time but intermittently. Is it too much of a coincidence or i might have now a prob with the fan or pcb? Can someone head me in the right direction as to how to troubleshoot such a problem please. Your help is much appreciated.

 

[lightning]

Check overheat switch at base of boiler hasn't tripped

 

[dotto]

Thanks m8 it was indeed the overheat reset button that had tripped....ooophhhh that has saved me a few quid for the call out...As far as the fan is concerned, as i mentioned beforehand, sometimes it keeps running even though the hw and ch are satisfied until i switch the boiler switch off manually, what could it be?? Fan problem or pcb and could i check them? Thanks again.

 

[twgas]

the microswitch, that was sticking, in the MV could well have caused the fan to run on. see what happens now you've got a new valve.